1. Field of Invention
This invention relates to sun shades for unoccupied motor vehicles, particularly to a collapsible sun shade deployed horizontally across the vehicle's interior.
2. Description of Prior Art
Exposure to sunlight is a major cause of deterioration of various parts of a vehicle's interior. Particularly susceptible to discoloration, deformation, and cracking are those parts which are made of plastic, vinyl, leather or cloth, such as the dashboard and seats. Expensive equipment such as stero speakers and telephone also need protection from the harmful effects of direct sunlight. In addition, continuous exposure to sunlight results in the steering wheel, gear shift handle, seats, and other interior parts becoming excessively warm to human contact, causing discomfort if not harm, to the driver and passengers.
Prior-art devices for shielding the vehicle's interior from the sun involve covering either the windshield, side windows, rear window, or dashboard by deploying individual devices inside the vehicle. Exemplary prior art devices are shown in U.S. Pat. No. 4,708,388 to Zacharczuk (1987), U.S. Pat. No. 4,762,358 to Levosky et al. (1988), U.S. Pat. No. 4,758,041 to Labeur (1988), U.S. Pat. No. 4,758,042 to Liu (1988), U.S. Pat. No. 4,749,222 to Idland (1988), and U.S. Pat. No. 2,991,119 to Young (1961). These devices leave certain portions of the vehicle's interior unprotected from sunlight. The portions which are unprotected depend upon the sun's angle which changes during the day. Although the entire interior could be protected using these devices by covering all the vehicle windows and the windshield, this requires the cumbersome task of deploying several individual units in different locations inside the vehicle.
Most external covers protect the entire vehicle's interior from direct sunlight by covering all the windows and the windshield. Typical of covers are shown in U.S. Pat. No. 4,684,165 to Becker (1987), U.S. Pat. No. 4,699,192 to Kamen et al. (1987), and U.S. Pat. No. 4,635,993 to Hooper et al. (1987). However, the primary purpose of these external covers is to protect the external finish of the vehicle. They compete with more popular and effective modern products, such as car waxes and sealants. These waxes and sealants offer the additional advantages of making the vehicle's finish shiny and more attractive, and protecting the vehicle's finish even during driving, which is when most of the dirt and other harmful natural elements are accumulated. External covers are also easily susceptible to theft and vandalism, and are cumbersome to install and store. They also hide signs of break-ins, such as shattered glass windows or damaged locks, thereby prolonging discovering thereof. In addition, since most external covers blanket the entire body of the vehicle, they are considered excessive and wasteful by those consumers who only want protection for the vehicle's interior. Due to these shortcomings, external covers are either not used regularly or not used at all.
The lower portion of the vehicle's interior located between the floor and the lower edge of the windshield, side windows, and the rear window, contains the interior parts, such as the dashboard, steering wheel, seats, and stereo equipment, which are susceptible to sunlight damage. This is also the portion of the interior with which the driver and passengers normally come in direct contact when the vehicle is occupied. Therefore, if this portion becomes excessively warm to human contact, it could cause discomfort, if not harm, to the driver and passengers. In addition, because this portion of the interior is bordered on the sides by the instrument panel, vehicle doors, and rear seats, it has considerably more insulation from the sun and external temperature than the upper interior portion, which, in comparison, is bordered by the windshield, glass windows, and the roof.